This application claims priority to International Application No. PCT/GB99/04107 which was published on Dec. 6, 1999.
The invention relates to a vacuum cleaner, particularly to a vacuum cleaner having a cleaner head.
Upright vacuum cleaners commonly include cleaner heads which are pivotably attached to the main body or casing of the vacuum cleaner to allow the main casing (which includes a handle) to be tilted away from to the vertical for conventional upright use. Examples of upright cleaners having pivotable cleaner heads are shown in EP 0 037 674 and EP 0 134 654. Many vacuum cleaners having similarly mounted cleaner heads are available on the open market. The pivotable connection between the cleaner head and the main casing also allows the cleaner head to lift away from the surface when small obstacles or irregularities in the floor surface are encountered by the cleaner head during the cleaning operation. However, the arrangement of known upright cleaners allows the respective cleaner head to move only in an arcuate manner with respect to the main body of the cleaner. When this type of lifting occurs, the cleaner head can become separated from the surface for longer than is necessary or desirable and cleaning can be unsatisfactory over some parts of the surface being cleaned.
Proposals have been made in respect of robotic vacuum cleaners. These are cleaners which are capable of operating independently of a user by making use of on-board navigation and control apparatus so as to be able to navigate around a closed environment, ie a room which is required to be cleaner, without becoming lodged against furniture in the room. In many of the prior art proposals, the cleaner head is located underneath the main body of the cleaner without being movable with respect thereto (see, for example, U.S. 5,109,566 and U.S. 5,682,640). These machines are designed to clean only smooth, regular surfaces and are therefore unsuitable for domestic use or use in any other environment where cleaning of a variety of different surfaces is required. In other proposals, for example, U.S. 5,781,960 and U.S. 5,534,762, the cleaner head is pivotably mounted on the underside of the main body or chassis so that it can float on the surface to be cleaned and this arrangement will allow the cleaner head to lift in a similar manner to that of the arrangement commonly found on upright cleaners. However, the cleaner head of each of these latter proposals still has the disadvantage that parts of the floor will not be cleaned adequately if obstacles or uneven surfaces are encountered.
It is an object of the present invention to provide a vacuum cleaner having a cleaner head which is capable of maintaining close contact with the surface to be cleaned even when small obstacles and/or uneven surfaces are encountered. It is a further object of the present invention to provide a vacuum cleaner which performs better than known vacuum cleaners when small obstacles and/or uneven surfaces are encountered. It is a still further object of the present invention to provide a vacuum cleaner having a cleaner head which is capable of remaining in a position which is substantially parallel to the surface to be cleaned, irrespective of the inclination thereof.
The invention provides a vacuum cleaner comprising a main body and a cleaner head movably mounted thereon, the cleaner head having a downwardly directed suction opening, characterised in that the cleaner head is mounted on the main body by means of at least one articulating member having a first end which is pivotably connected to the cleaner head and a second end which is pivotably connected to the main body.
The provision of at least one articulating member pivotably connected at one end to the cleaner head and at the other end to the main body allows the cleaner head freedom of movement to follow the contours of the surface to be cleaned if they are uneven. It also allows the cleaner head to climb over small obstacles without coming out of contact with the surface for longer than is absolutely necessary. If two such articulating members are provided parallel to one another and spaced along the cleaner head, the arrangement is particularly effective in allowing freedom of movement whilst still maintaining the correct alignment of the cleaner head with respect to the main body of the vacuum cleaner.